def from_hfile(cls, hfile):
nwys = hfile["nwys"].value
nwx = hfile["nwx"].value
xshifts = hfile["xshifts"].value
yshifts = hfile["yshifts"].value
y0 = hfile["y0"].value
daz = hfile["daz"].value
scan_speed = hfile["scan_speed"].value
ncomp = hfile["ncomp"].value
dtype = np.dtype(hfile["dtype"].value)
header = astropy.io.fits.Header()
hwcs = hfile["gwcs"]
for key in hwcs:
header[key] = hwcs[key].value
gwcs = enwcs.WCS(header).sub(2)
return cls(nwys,
nwx,
xshifts,
yshifts,
y0,
daz,
scan_speed,
gwcs,
ncomp=ncomp,
dtype=dtype)
def build_workspace_wcs(res):
wcs = enwcs.WCS(naxis=2)
wcs.wcs.cdelt[:] = res
wcs.wcs.crpix[:] = 1
wcs.wcs.crval[:] = 0
# Should really be plain, but let's pretend it's
# CAR for ease of plotting.
wcs.wcs.ctype = ["RA---CAR", "DEC--CAR"]
return wcs
def build_fullsky_geometry(res):
nx = int(np.round(360 / res))
ny = int(np.round(180 / res))
wcs = enwcs.WCS(naxis=2)
wcs.wcs.cdelt[:] = [-res, res]
wcs.wcs.crpix = [1 + nx / 2, 1 + ny / 2]
wcs.wcs.crval = [0, 0]
wcs.wcs.ctype = ["RA---CAR", "DEC--CAR"]
return (ny + 1, nx), wcs
def make_projectable_map_by_pos(pos,
lmax,
dims=(),
oversample=2.0,
dtype=float,
verbose=False):
"""Make a map suitable as an intermediate step in projecting alms up to
lmax on to the given positions. Helper function for alm2map."""
# First find the theta range of the pixels, with a 10% margin
ra_ref = np.mean(pos[1]) / utils.degree
decrange = np.array([np.min(pos[0]), np.max(pos[0])])
decrange = (decrange - np.mean(decrange)) * 1.1 + np.mean(decrange)
decrange = np.array(
[max(-np.pi / 2, decrange[0]),
min(np.pi / 2, decrange[1])])
decrange /= utils.degree
wdec = np.abs(decrange[1] - decrange[0])
# The shortest wavelength in the alm is about 2pi/lmax. We need at least
# two samples per mode.
res = 180. / lmax / oversample
# Set up an intermediate coordinate system for the SHT. We will use
# CAR coordinates conformal on the equator, with a pixel on each pole.
# This will give it clenshaw curtis pixelization.
nx = utils.nint(360 / res)
nytot = utils.nint(180 / res)
# First set up the pixelization for the whole sky. Negative cdelt to
# make sharp extra happy. Not really necessary, but makes some things
# simpler later.
wcs = enwcs.WCS(naxis=2)
wcs.wcs.ctype = ["RA---CAR", "DEC--CAR"]
wcs.wcs.crval = [ra_ref, 0]
wcs.wcs.cdelt = [360. / nx, -180. / nytot]
wcs.wcs.crpix = [nx / 2.0 + 1, nytot / 2.0 + 1]
# Then find the subset that includes the dec range we want
y1 = utils.nint(wcs.wcs_world2pix(0, decrange[0], 0)[1])
y2 = utils.nint(wcs.wcs_world2pix(0, decrange[1], 0)[1])
y1, y2 = min(y1, y2), max(y1, y2)
# Offset wcs to start at our target range
ny = y2 - y1
wcs.wcs.crpix[1] -= y1
# Construct the map. +1 to put extra pixel at pole when we are fullsky
if verbose:
print "Allocating shape %s dtype %s intermediate map" % (
dims + (ny + 1, nx), np.dtype(dtype).char)
tmap = enmap.zeros(dims + (ny + 1, nx), wcs, dtype=dtype)
return tmap
def __exit__(self, type, value, traceback):
sys.stderr.write("%6.2f %6.3f %6.3f %s\n" %
(time.time() - self.t1, memory.current() / 1024.**3,
memory.max() / 1024.**3, self.desc))
with dprint("spec"):
ps = powspec.read_spectrum(args.powspec)[:ncomp, :ncomp]
# Construct our output coordinates, a zea system. My standard
# constructor doesn't handle pole crossing, so do it manually.
with dprint("construct omap"):
R = args.radius * deg2rad
res = args.res * min2rad
wo = wcslib.WCS(naxis=2)
wo.wcs.ctype = ["RA---ZEA", "DEC--ZEA"]
wo.wcs.crval = [0, 90]
wo.wcs.cdelt = [res / deg2rad, res / deg2rad]
wo.wcs.crpix = [1, 1]
x, y = wo.wcs_world2pix(0, 90 - R / deg2rad, 1)
y = int(np.ceil(y))
n = 2 * y - 1
wo.wcs.crpix = [y, y]
omap = enmap.zeros((n, n), wo)
# Construct our projection coordinates this is a CAR system in order
# to make interpolation easy.
with dprint("construct imap"):
ires = np.array([1, 1. / np.sin(R)]) * res / args.supersample
shape, wi = enmap.geometry(pos=[[np.pi / 2 - R, -np.pi],